The roofing tiles and hoizontally oriented rafters of the roof need to be removed, the aluminium sheet applied on the verticall oriented roofing beams and the rafters screwed back on the sandwich the aluminium sheet and then the roofing tiles have to be relaid on the rafters.

I have a 1200 sqft home. I am putting another layer of composite shingles on my roof. I'm looking to hire someone who has shingle experience to help me. The person needs to have experience and is comfortable with valleys and vents, and flashings. This a 2 day job.